It has taken four months and 11 goalless first-halves at Old Trafford for Manchester United to remember how to kill a game inside 45 minutes, but finally the old swagger returned to blow Stoke away.

Wayne Rooney maintained a scoring streak which now stands at seven goals in seven games, Anthony Martial embellished an outstanding display with a breathtaking goal and Juan Mata pulled strings that many inside the stadium had forgotten had existed as Louis van Gaal's team secured the victory crucial to keep pace with the top four.

When United were humbled 2-0 at Stoke on Boxing Day, Van Gaal's position appeared untenable, with supporters calling for his head as he walked down the touchline at the Britannia Stadium.

But while the recent revival has been a slow-burner, this victory suggested United can still close the gap on Champions League qualification and perhaps even threaten a late surge towards the top spot.

That remains unlikely, but momentum is everything in football and, as they prepare to travel to Chelsea on Sunday, they can at last claim to be on an upward trajectory again.

Manager Van Gaal was quick to hail the performance of 30-year-old Rooney who took his tally to 244 United goals, putting him only five behind record-holder Sir Bobby Charlton and Van Gaal wants the England international to overhaul the World Cup winner this season.

"I hope for him and it is also good for me then because when he scores, we win," he said.

"Everybody has forgotten he was a substitute against Stoke City away.

"It is for everybody always the same with me. You have to prove it every game, every training session and then you play. When he plays like this, I cannot say to him: 'Go to the bench'."

Jesse Lingard and Martial were United's other scorers and Dutchman Van Gaal was delighted with the quality of their goals.

"Superb," he said. "These were team goals building up from behind and team goals I like the most.

"Of course I am very happy with an individual goal also but these were team goals and the finishing was also very good."

Van Gaal admitted he is surprised by the impact Martial has had at Old Trafford since United paid Monaco an initial £36 million for the teenager in the summer.

"He is 19, now he is 20. That is surprising," he said.

"You come from the French league to the Premier League and you can do this. You are 19-years-old then you have a lot of potential to give still but then I (will not be) the manager when he is at his best."

Martial has excelled as a winger of late and Van Gaal suggested he will stay there, just as Rooney will remain his main striker and Mata his No. 10.

"He likes to play in a striker's position more than where he is now playing but when he plays like this I am not changing," he added.